I am looking for a simple way to have my users failover internet traffic if our primary line fails. Currently I have a 100/100 fiber connection to the internet running through an asa5515x. I also have a aDSL line running on a 2801 series router handling some failover tunnels to remote sites. As of today if for some reason our fiber line were to fail I can manually change our default route on our 3750x switch stack to point to the 2801 and users can surf again.
In my head I am thinking what I could do is put a router in front of all of this and do something like IP sla? If multiple icmp echo tests fail on the fiber connection it would automatically remove the route and fail to the DSL.
Would this be the easiest way to handle an automatic failover of the default route from one direction to another?